I'm no expert, but from what I imply from general coverage I've seen is that a lot of the cashflow is spoken for in operating Saudi gov't, public basic-income l

I'm no expert, but from what I imply from general coverage I've seen is that a lot of the cashflow is spoken for in operating Saudi gov't, public basic-income like payments, and family / ruling class payments. Again my guess, but making the case you need to cleanup the company finances for external investors and public accounting purposes may have been easier than trying to separate it out outright internally - either for the purpose of better long term diversification or, maybe, for the more cynical interpretation of gaining more family control of the asset of Aramco. Norway was pretty unique in that early on they decided to route most of the cashflow into their fund. They're an (the only?) exception to what has been called the resource curse. Oil riches usually don't work out as well as in Norway.